Long-term Effects Of Knitted Silk-Collagen Sponge Scaffold On Anterior Cruciate Ligament Reconstruction And Osteoarthritis Prevention

Background and ObjectivesAnterior cruciate ligament (ACL) plays an important role inproviding stability to the knee and enabling functional movements. Its injury is very common in orthopedic surgery department. Due toits relativelyavascular nature, limited seed cells, and the dynamic fluid environment ofjoint,ACL has a limited capacity to regenerate, and the functional repair of ACL injury remains a formidable clinical challenge.Current surgical management of ACL rupture consists of reconstruction with autograft or allograft rather than primary repair as a golden standard. However, these therapeutic outcomes are limited byinevitable donor site morbidity,poor graft integration, and high rates of recurrent tearing.Up to date, artificial ligaments are emerging as a promising alternativetreatment approach.Previouscommercialproducts such as Leeds-Keio(?), Proplast(?), Gore-Tex(?) andStryker-Dacron(?)were fabricated from non-degradable syntheticmaterials. Although they overcome the deficienciesof autografts and allografts and exert satisfactory effects in theshort term, they induce certain adverse effects in the long term,including graft rupture, OA occurrence, chronic synovitis, andforeign body reaction.Recentlysilk-based biomaterials are being widely utilized insoft tissue engineering due to their good biocompatibility andremarkable mechanical strength. Previously, we have achieved satisfactory regeneration of subcutaneous tendon/ligament withknitted silk-collagen sponge scaffold due to its specific "internal-space-preservation" property. Thisstudy aims to investigate the long-term effects of knitted silk-collagen sponge scaffold on ACL regeneration and osteoarthritis prevention.Methods and ResultsThe knitted silk-collagen sponge scaffold was fabricated andimplanted into a rabbit ACL injury model. The knitted silk-collagen sponge scaffold was found toenhance migration and adhesion of spindle-shaped cells into the scaffold at2months post-surgery, After6months, ACL treated with the knitted silk-collagen sponge scaffold exhibited increased expression ofiigament genes and better microstructural morphology. After18months, the knitted silk-collagensponge scaffold-treated group had more mature ligament structure and direct ligament-to-bone healing.Implanted knitted silk-collagen sponge scaffolds degraded much more slowly compared to subcutaneous implantation. Furthermore, the knitted silk-collagen sponge scaffold effectively protected jointsurface cartilage and preserved joint space for up to18months post-surgery. ConclusionThese findings demonstrated that the knitted silk-collagen sponge scaffold can regenerate functional ACL and preventosteoarthritis in the long-term, suggesting its clinical use as afunctional bioscaffold for ACLreconstruction.